The present invention relates generally to welding systems and, more particularly, to an apparatus for autothreading welding wire from a welding wire supply source through a welding gun of a welding system.
Welding systems and, in particular, automatic or robotic welders are well suited for high output industrial applications such as those more commonly found in machine shops and automobile manufacturing facilities. As such, considerable amounts of wire are consumed during the welding process often resulting in xe2x80x9cdown timexe2x80x9d for re-supplying wire from a wire source to the robotic arm of the automated welding system.
When the supply of welding wire being supplied to the welding system is depleted, the welder or operator of the system typically will first grasp the end of the welding wire protruding from the tip of the welding gun with a pair of pliers and pull out any welding wire remaining in or extending from the gun. Thereafter, the operator will replace the empty welding wire spool and replace it with a new spool of welding wire. The loose end of the new spool of welding wire is then threaded through various guides and conduits extending to a wire feeder assembly whereupon the welding wire is driven by a drive assembly so as to thread the wire through the welding gun until the welding wire exits the gun tip. Typically, excess welding wire extends past the gun tip as a result of over-threading which must be manually trimmed, or in the case of a robot welding process, an automatic cutter may be implemented. Thereafter, the welding system is ready to resume the welding process.
A number of systems have been developed to reduce the aforementioned down-time associated with manually feeding wire from a new supply to the welding gun by implementing an apparatus that automatically connects the welding system to a fresh wire supply source upon depletion of welding wire on the current supply. However, these systems for automatically connecting to a fresh wire supply as well as the aforementioned manual feed systems require the welder or operator of the welding system to control the initial feeding of wire from the wire supply to the tip of the welding gun. This manual control of the initial feeding of wire from the supply to the tip of the welding gun customarily requires the welder to depress or hold a jog button on a welding system interface until the wire is fed from the wire supply to the tip of the gun. As a result, the welder would typically over depress the jog button thereby resulting in wire being fed past the tip of the welding gun. This xe2x80x9cover-shootingxe2x80x9d of the gun tip then requires the welder to either retract or trim the wire. Electing to trim the excess wire then results in unused welding wire being discarded as waste thereby resulting in higher wire consumption and costs. Retracting the wire is also problematic as the welder must then depress a retract button for the appropriate time so as to not retract the wire past the gun tip. This repetitive depressing of the jog and retract buttons to achieve proper placement of the welding wire in the gun is time consuming and results in unnecessary and unwanted down time for the welding system thereby leading to manufacturing delays and increased manufacturing costs.
It is therefore desirable to design a system whereupon a precise amount of welding wire is fed to the gun of a welding system such that the wire need not be trimmed thereby reducing wire waste and operational delays.
The present invention is directed to an autothread wire feeding system overcoming the aforementioned drawbacks. Specifically, the present invention is directed to a control that upon detection of an autothread input determines the amount of time in which a motor of a wire feed drive assembly should be activated so as to precisely supply an initial segment of wire to a welding gun of a welding system. The control which may be implemented as software, hardware, or a combination of both determines the requisite time necessary to precisely thread the welding wire based on the wire feed speed and gun length of the system. The gun length and wire feed speed may be determined from a series of user inputs or read from memory stored on a storage device in the welding system. By limiting user involvement with the actual xe2x80x9cfeedingxe2x80x9d of wire to the welding gun, a more precise segment of welding wire may be fed to the welding gun such that trimming of wire extending past the tip of the welding gun is not needed. The present invention may also be implemented as a testing tool to confirm proper feeding of wire from the wire supply to the welding gun.
Therefore, in accordance with one aspect of the present invention, a control operable with a wire feeder of a welding system is provided and configured to receive an autothread input from a user. The control is also configured to determine a time required for welding wire to thread through a prescribed length at a prescribed wire feed speed. The control is further configured to activate a motor configured to drive welding wire from a wire source at the prescribed wire feed speed and for the determined time until a segment of welding wire having the prescribed length is fed.
In accordance with another aspect of the present invention, a power source/interface unit configured to drive a wire drive assembly is provided. The power source/interface unit includes a robot control receptacle configured to communicate with a robot controller as well as a peripheral control configured to communicate with a drive assembly of a welding robot having a welding gun. The interface further includes a processor configured to execute a set of instructions that when executed causes the processor to receive an autothread user input and determine from a set of wire feed inputs a motor control signal. The motor control signal is configured to drive the drive assembly to minimally thread wire through the welding robot to the tip of the welding gun. The processor is further caused to output the motor control signal to the drive assembly.
In accordance with yet another aspect of the present invention, a computer readable storage medium having a computer program stored thereon and representing a set of instructions that when executed by a computer causes the computer to detect an autothread command on an interface of a welding system is provided. The set of instructions further causes the computer to access a plurality of wire feeding parameters and determine a threading time therefrom. The computer program then causes the computer to activate a motor of a drive assembly of a welding gun for the threading time to supply a segment of wire to the welding gun.